It also asserts that responding effectively to hazards posed by NEOs requires national and international cooperation. The book explores four main types of mitigation including civil defense, 'slow push' or 'pull' methods, kinetic impactors and nuclear explosions. Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies identifies the need for detection of objects as small as 30 to 50 meters as these can be highly destructive. In 2005, a Congressional mandate called for NASA to detect 90 percent of NEOs with diameters of 140 meters of greater by 2020. A significantly smaller amount of funding supports ways to protect the Earth from such a potential collision or 'mitigation.' This, however, is insufficient in detecting the majority of NEOs that may present a tangible threat to humanity. The majority of this funding supports the operation of several observatories that scan the sky searching for NEOs.

The objective is to detect those that may collide with Earth. The United States spends approximately $4 million each year searching for near-Earth objects (NEOs). Division on Engineering and Physical Sciences.Division of Behavioral and Social Sciences and Education.Help Ordering Information New Releases Browse by Division Browse by Topic

Space engineers planets download free